Water tube steam boiler



Jan. 12, 1932. G. w. BACH WATER TUBE STEAM BOILER Filed March 18, 1929 my I Patented Jan. 12, 1932 UNITED sures PATENT 7 OFFICE GIDCRGE 1w.

-ERIE,(PENN' SYLVANIA,.A CORPORATION OF PENNSYLVANIA WATER TUBE :s'rm. BOILER Application 'filfid March 16, 1929. Serial No. 347,776.

' This invention relates to water tube: steam boilers, and particularly to :boilers for high temperature furnaceconditions and h gh ratings required in present day installations.

' The invention contemplates :circulation of wate'rtothe lower drum for: assuring proper Watersupply to the front clement ottheboiler to prevent ruptureofzthe tubes Lof'ithe front elementorother damage shouldlthebafile fail. Also should the baflie fail "and all the :tnbes then become upflow tubes, the water: supplied to the lower front drum would therefore prevent overheating of these tubes and :consequent rupture of the same. n

An object of the invention 18 to provide a water 'tube' 'steain boiler having -:largesheating surface arranged to receive heat direetlyfrom the fire by radiationand with-water circulation to the front heating'element of the'boiler.

Another object of the inventionistoiprovide a water tube steam'boiler'havinga large combustion chamber of A" shape at the front of the boiler with-a bank: of tubes'as "a front element arranged to "protect the front wall from the furnace heat together with means for 'supplyin'g 'waterto the front element.

A-f-urther object of thei invention is. to provide a water tube steamiboiler having a combustion chamber of A shape with a bank of tubes forthe front elementthereo'f in which element certain tubes are separated from .certa-in other tubes by a battle for creating a thermal siphon effect in the front element together with IHGQLIISZEOI supplying water to the front element in: case of failure of such baffie to thereby prevent rupture ofthe tubes which otherwise would occur due to overheatingof thetubes.

a A still further object of the invention is to improvewater tubesteam boiler constructionbyproviding water supply to the front tubes: thereof to: prevent overheating of such tubes that might otherwise occur should certain'parts of the boiler structure burn out in service.

vALSt/lll fnrtherobject of the inventionis to rovide water supply toboilers ofthe N type which will-increase the v eiliciency ofithe' same in use.

,[lhe above, other,::and:-;further obiects of the invention will be apparent from the following description, accompanying drawing, andappended claim. a

.'i .LCCOICll1lg:tO the invention water issupplied to the lower front drum of the :front element a or: tubes soithatin the eventithebaffie wall separating certain tubes of thefront element fail -then the water supply would prevent overheating of these tubes with consequentruptureof the same and also at the same time assuring proper water supply for efiici'ent operation of the-boiler.

The :form OfrbQllQl' chosen-to. exemplify the invention :isrillustrated in connection witha boiler ofthe'N shape type and it isto be understooduthat the invention is of course susceptible of usc-with boilers of other arrange ment'th-an that illustrated anddescribed.

The illustrated boiler has an upper front steam and water drum 1, an upper rear-steam and water drum 2 which drums are connected by asbanl; of steam tubes 3 andabankof'watertubes 4. The drumsl and 2 are parallel to each other and as illustrated are-arranged transversely of the boiler-setting. I

A lower rear water drum '5 is arranged parallel to the drums 1 and-2. Afront'lower waterldrurnfiis suitably supported inthe front Wall? of the boiler setting.

The drums Land 5 are connected by banks of tubes 8 and 9 which tubes maybe-curved or straight or. partially curved and partially straight.

The lower front drum 7 6 and the upper front drum 1 are connected by banks of tubes 10 and 11 which: tubes may be straight or curved or straight and curved. A. bafile wall 12 is arranged betweenrthe tubeslO and the tubes 11 of the two banks, the banks 10 and 11 constitutingwhat is referred to herein as the front element of theboiler. The combustion chamber is 'A shaped 1 being defined by 1 the front elementand also by the banks of tubes 8 and;'9 connecting the drums land 5.

.The drums2 and 5 are connected by a bank of tubes 13 which may be of suitable arrangementzuand curvature'to meet properoperating conditions.

Azbafile wall 14ll$ arranged-between certain of the tubes of the bank 9 which wall extain distance.

' from the furnace thus tends upwardly from the lower rear drum 5 towards the upper front drum 1 terminating in a substantially vertical wall or partition 15.

A wall 16 extends downwardly from the upper rear drum 2 towards and terminates short of the lower rear drum 5 with an angularly disposed wall 17 extending forwardly from the wall 16 towards the bank 9 of tubes and lying alongside of said bank for a cer- The zone or chamber included between the walls 14, 15, and 16 serves as a superheating zone or chamber wherein any suitable superheater may be installed if desired.

A lining 18 is arranged between the outer bank of the tubes of the front element and the front wall 19 of the boiler structure. Likewise the steam tubes 3 are protected by a lining 20 while the lower front drum 6 is protected also by a continuation of the'lining 18 downwardly and extending around this drum.

'A water pipe 21 is connected between the lower drums 5 and 6 so as to supply water to the lower front drum 6 while the boiler is in use.

Tubes 22 are arranged at the rear ofthe furnace or combustion chamber A and communicate with the interior of the drum 5 at one end of said tubes while the other ends are secured to connections 23 from which extend upwardly pipes 21 which pipes enter the drum 5, so that heating of the water within the drum 5 may beaccomplished by the heat preliminarily heating the'water supplied to the drum 5.

The furnace may be supplied with any type or kind ofvstoker orgrates as desired and fired in any chosen manner. This feature forms no part'of thisinvention andtherefore it not illustrated as it is well understood in boiler construction that any suitable or desirable type of grate or stoker may be employed in boilers of this character.

A plurality of hook plates are provided for supporting hook blocks or similar lining structures within the'boiler setting for obvious purposes. v

The operation of the boiler as illustrated is. as follows Water is supplied from any convenient sourceand fills the drums and tubes as indicated in the drawings. As the water is heated there will be a thermal siphon effect set up in the front element with circulation of rear drum 5. Should the bafiie 12 between the tubes 10 and 11 of the front element fail for any reason then the circulation through the tubes 10 and 11 would be upwards or in other words these tubes would become upfiow tubes and the thermal siphon effect would be stopped the supply of water to the lower front drum 6 from the rear drum 5 would therefore preventzoverheating of the tubes 10 and 11 as the water supplied to the front drum '6- would enter 'these tubes and thus become vaporized into steam and at the same time prevent overheating of the tubes because of the circulating of the water throughthe same.

The lower front drum 6 is supplied with water at all times from the lower rear drum 5 because of the pipe 21 connecting these drums. The front drum 6 issmaller in diameter than the rear, drum 5 and is arranged in such relationv to the vertical height of the rear drum 5 as to insure circulation from the drum,5 to the drum 6 at all times.

i The provision of the bafllewall 12 results in a definiteiand rapid circulation of water on the tubes 10 and 11 creating the thermal siphon elfectas the tubes 10 are protected by the baflle wall 12 fromthe heat of the gases in the combustion chamber A. The contents of the tubes 11' exposed to the gases of combustion consist of part water and part steam while the tubes 10 contain water thereby creating a rapid circulation in the direction indicated by the arrows. Furthermore, the provision of the baffle wall 12' protects the front wall 19 of the boiler from radiation losses so that the front wall may therefore be thinner than otherwise. 7 I

Circulation through the tubes 8 between the drums 1 and 5 will be upwardly that is from the drum 5 to the drum 1,;whereas circulation in the tubes 9 will be downwardly as the tubes 8 are exposed to the gases of combustion more directly than are the tubes 9. The battle wall 14 serves to deflect. heat from certain of the tubes 9 for apart of the length of the same for increasing the efficiency of the circulation and thereby the efficiency of the boiler.

Whatever waterthere may be in the upper rear drum 2 that is'cool passes downwardly through-the tubes 13 to the lower rear drum 5' for reentering circulation.

The water in the drum 5 is preheated to a certain 'extent by circulation downwardly through the-pipes 24 and upwardly through pipes 22. A blow off flange 25 is provided in the headerv 23 to eliminatesediment and the like; i

The superheater zone or space B is substan tially V shaped while the combustion chamberA is A shaped. This arrangement of the tubes makes possible operation of a boiler under high temperatures and with high ratmgs.

v The water entering the tubes 8 and 11 from the drums 5 and 6 respectively does not come in contact with any steam or water from the hotter parts of the boiler thus adding to the efiiciency of the same. It will be observed also that the boiler of this invention has a very large direct heating surface with a small amount of furnace wall subjected to the intense heat'of the fire.

The bafile wall 12 is arranged transversely of the boiler setting and is coextensive with I the length of the tubes 10 and 11 of the front element, thus extending substantially the entire length of said bankof tubes and positioning certain of said tubes as 10 between the baffle plate 12 and the front wall 19.

The invention has been described herein more or less precisely, yet it is tobe understood that changes may be made in the arrangement and proportion of parts and that equivalents may be substituted without departing from the spirit and scope of the invention.

The invention is claimed as follows:

A water tube boiler of the N-shaped type having a furnace wall and a combustion chamber at the front end thereof, front and rear transverse steam and water drums, said pair of drums being connected to each other by an upper bank of steam tubes and a lower bank of water tubes, a lower front water drum, a bank of tubes longitudinally positioned adjacent said wall connecting said water drum and said front water and steam drum, a baffle plate placed transversely between said tubes and extending longitudinally thereof substantially the entire length of said bank of tubes with a row of said tubes positioned between said baffle plate and wall, a lower rear water drum of larger diameter than that of said front water drum, the bottoms of said drums being at substantially the same level, a bank of tubes connecting said lower rear water drum and said front water and steam drum to define with the tubes connecting said front water drum and said front water and steam drum an A-shaped furnace space, another bank of tubes connecting said lower rear water drum and said rear water and steam drum to define a V-shaped superheater space with a bank of tubes connecting the rear water drum and the front water and steam drum, the tube banks connecting the rear water drum and the steam and water drumshaving more tubes than the bank con necting the front water drum to the front steam and water drum, and a pipe connecting the bottom of the rear water drum and the bottom of the front water drum extending substantially horizontal therebetween.

In testimony whereof I have hereunto subscribed my name at Erie, Erie County, Pa.

' GEORGE W. BACH. 

